This application relates to the art of testing apparatus and methods and, more particularly, to such apparatus and methods for testing products for air leaks. The invention is particularly applicable for use in testing valves and the like for leaks. However, it will be appreciated that other products having separate air chambers normally charged to different pressures can also be tested with the apparatus and method of this application.
Certain products, such as air valves and the like, have a certain permissible maximum combined leak from primary and secondary air chambers. The use of a single supply air source for supplying both primary and secondary air chambers requires a pressure regulator for pressurizing the secondary air chamber to a secondary air pressure substantially lower than the primary air chamber. The use of conventional pressure regulators makes it difficult to measure for leaks because standard pressure regulators have a built in leak which adds to any leakage occurring through the product.
It would be desirable to provide an arrangement for regulating secondary air pressure without having any leaks in the supply path so that any indicated air flow on an air flow indicating device represents a leak through the product being tested.